With the wide use of the LCD panel, LCD manufacturing is one of most popular industries. For an example of thin film transistor (TFT) LCD, i.e. a non-emission display, it is necessary to assemble the TFT LCD with a backlight module served as a light source besides an LCD panel for controlling the display screen. Conventionally, the backlight module includes a direct-type lighting module and an edge-type lighting module wherein the edge-type lighting module is widely utilized.
Based on the design requirement of the backlight module in the LCD, a variety of standards with different brightness and color chromaticity are adopted. However, the efficiency of LCD has to be considerably increased to meet tightly high requirement. Thus, the brightness, the amount or lighting power of LED, of the light source cannot be invariably enlarged to enhance the illumination of the backlight module. The film structures of the backlight module may be arranged to adjust the brightness of the backlight module.
After the film structures with different brightness gains are selected, the brightness and chromaticity of the backlight module may be adjusted though. However, the light convergence, the transmittance rate and the material of the film structures may be changed according to different film structures. Even if the film structures are different, however, their transmittance rates are the same so that the light guide plate under the film structure easily results in pattern mura effect. That is, after the brightness gain of the film structure is generated, the pattern mura effect occurs since the LGP assembled with the film structure is changed. The parameters of the film structure can be generated by try and error method to from the film structure for the identification of pattern mura. However, this manner will spend a lot of labor power and manufacturing cost, which results in the delay of the producing procedure.
Consequently, there is a need to develop a novel selecting method of LGP to solve the aforementioned problems of labor cost and manufacturing cost while producing the backlight module.